Monday, September 30, 2013

Stephen Asma argues that, because philosophers have failed to formulate a criterion to distinguish science from pseudo-science, the claims of traditional Chinese medicine cannot be dismissed. But it turns out that all that he thinks important is whether the treatments are effective—a question that he thinks immune to critical examination because it is not the sort of thing about which professional philosophers can engage in a lot of sophisticated-sounding talk.

Is The Stone, the philosophy blog of the New York Times, meant to be a platform on which professional philosophers can commit the intellectual equivalent of soiling themselves in public, or is my perception just biased by my attention to a few bad examples? I don’t know, but a piece by Stephen Asma published yesterday, “The Enigma of Chinese Medicine” (The Stone, September 29, 2013), certainly falls within the category of public trouser-fouling. Actually, it is an example of something even more contemptible than that: the employment of philosophical sophistication in the service of intellectual confusion.

The argument of Asma’s piece, to the extent that it has one, is that, because philosophers have failed to solve the problem of demarcating science from pseudo-science, one cannot reject the claims of certain “alternative” medical practices, specifically traditional Chinese medicine (“TCM”) and feng shui. After opening with an anecdote about how he recovered from a cold shortly after ingesting a Chinese preparation of freshly spilled turtle blood and strong liquor, Asma intimates that one cannot rule out the possibility that the Chinese concoction has curative powers because of the persistence of what philosophers of science call “the demarcation problem”:

The contemporary philosopher of science Larry Laudan claims that philosophers have failed to give credible criteria for demarcating science from pseudoscience. Even falsifiability, the benchmark for positivist science, rules out many of the legitimate theoretical claims of cutting-edge physics, and rules in many wacky claims, like astrology — if the proponents are clever about which observations corroborate their predictions. Moreover, historians of science since Thomas Kuhn have pointed out that legitimate science rarely abandons a theory the moment falsifying observations come in, preferring instead (sometimes for decades) to chalk up counter evidence to experimental error. The Austrian philosopher Paul Feyerabend even gave up altogether on a so-called scientific method, arguing that science is not a special technique for producing truth but a flawed species of regular human reasoning (loaded with error, bias and rhetorical persuasion). And finally, increased rationality doesn’t always decrease credulity.

We like to think that a rigorous application of logic will eliminate kooky ideas. But it doesn’t. Even a person as well versed in induction and deduction as Arthur Conan Doyle believed that the death of Lord Carnarvon, the patron of the Tutankhamen expedition, may have been caused by a pharaoh’s curse.

Setting aside the appeals to authority, Asma’s main claims here are these: (1) No one has identified a reliable criterion for distinguishing science from pseudo-science. (2) No one has given a credible specification of a method distinctive of science. (3) Increased rationality or practice in induction and deduction does not always decrease credulity toward kooky ideas.

The third claim seems pretty clearly irrelevant to Asma’s thesis. The case of Arthur Conan Doyle’s belief in the curse of Tutankhamen (it is disappointing that Asma does not cite the more instructive case of Doyle’s belief in the Cottingley fairies) might be of some relevance if it were an instance in which someone was led to supernaturalistic conclusions by sound deductive and inductive reasoning (supposing such a thing to be possible). But it is not; it is an instance of the distortion of judgment by cognitive bias. Such cases remind us that cognitive bias afflicts all human beings without exception. That is precisely why we need instruction in deductive and inductive reasoning, as well as knowledge of the cognitive biases themselves: only then can we, sometimes, rise above our worse selves and correct our judgment in empirical matters when it goes awry. But, as Asma makes no further reference to these observations in his piece, I will say no more about them.

What of the first two claims? Granted, for the sake of argument, that there is no known universal criterion or distinctive method demarcating science from pseudo-science, how is that supposed to lend credibility to the claims of traditional Chinese medicine? Asma never makes this clear, but the implied reasoning seems to be this: “Many people dismiss traditional Chinese medicine as pseudo-science; but there is no way to distinguish in principle between science and pseudo-science; therefore, one cannot dismiss traditional Chinese medicine.” If this is the intended argument, it fails on two scores. In the first place, the fact that one cannot give a universal criterion for distinguishing A from B does not show that there is no difference between A and B, or that one is unjustified in identifying something as an instance of A and not of B. There is, for example, no commonly accepted explanation of the distinction between right and wrong: it doesn’t follow that one can’t soundly and justly judge of some action that it is wrong. Second, even if Asma could show that traditional Chinese medicine escapes the charge of pseudo-science, it would not follow that its claims have the slightest degree of credibility. “Scientific” doesn’t imply “warranted” or “sound,” and “not pseudo-science” doesn’t imply “not a load of bollocks.”

I have said that this seems to be Asma’s argument, but in the end it is not clear that Asma even intends to make an argument. What we get instead in the conclusion of the piece is just a certain insinuation. After providing a second anecdote of his undergoing a treatment by traditional Chinese medicine and subsequently feeling decidedly better, he concludes the piece with these paragraphs:

It seems entirely reasonable to believe in the effectiveness of T.C.M. [traditional Chinese medicine] and still have grave doubts about qi. In other words, it is possible for people to practice a kind of “accidental medicine”—in the sense that symptoms might be alleviated even when their causes are misdiagnosed (it happens all the time in Western medicine, too). Acupuncture, turtle blood, and many similar therapies are not superstitious, but may be morsels of practical folk wisdom. The causal theory that’s concocted to explain the practical successes of treatment is not terribly important or interesting to the poor schlub who’s thrown out his back or taken ill.

Ultimately, one can be skeptical of both qi and a sacrosanct scientific method, but still be a devotee of fallible pragmatic truth. In the end, most of us are gamblers about health treatments. We play as many options as we can; a little acupuncture, a little ibuprofen, a little turtle’s blood. Throw enough cards (or remedies), and eventually some odds will go your way. Is that superstition or wisdom?

If this is the summation of Asma’s position, then the preceding references to the demarcation problem, far from being an argument, are just a sort of preparatory entertainment and are inessential, if not altogether irrelevant, to his main point. According to what Asma says here, it makes no difference whether traditional Chinese medicine is science or pseudo-science, because the legitimacy of its theoretical claims—about qi and so forth—is irrelevant to claims of its effectiveness. The “fallible pragmatic truth” of such claims is what really matters.

Notice what has happened here. Having spent most of the piece considering the theoretical claims of traditional Chinese medicine and invoking the demarcation problem to argue—by a villainous non sequitur—that because we can’t solve the problem, we can’t dismiss such claims, he now says that it is only the claims of effectiveness that matter. And with regard to such claims, he coyly suggests, we are wise to take a chance on the treatments because we can’t know that the claims for them are false.

What sort of claim is Asma talking about here? And how are such claims to be assessed? Notice that there is a world of difference between claims of the following two sorts:

(1) I underwent treatment T, and subsequently my headache went away.

(2) Treatment T is effective against headache.

Obviously, the second claim is much stronger than the first. For one thing, it has a generality to it that the first lacks. But more than that, it asserts a causal connection that the first one does not. To establish claim (1), all that is needed is evidence that the speaker had a headache before she underwent T and ceased to have it afterward. To establish claim (2), we require evidence (a) that quite generally people with headaches who undergo T lose those headaches after undergoing T and (b) that this is not due to factors extraneous to T, such as the headaches going away by themselves. Anecdotes on the lines of claim (1) can support point (a), and many people content themselves with finding evidence of this nature—a manifestation of confirmation bias. But such anecdotes, no many how many in number, fail to establish, or even to support, claim (2) if they are not supplemented by evidence supporting point (b). That sort of evidence is by far the more difficult sort to procure. It requires experimental controls, such as blinding and, optimally, even double-blinding (arranging that neither the administrator nor the recipient of the treatment knows whether T is being administered or not). And, of course, in any study of such matters, the significance of the results must be assessed according to the size of the sample, the basis of selection, possible sources of bias, and so forth. Such considerations are the ABCs of the “scientific method” on whose existence sophisticated philosophers of science like Feyerabend (invoked by Asma in the passage quoted earlier) would cast such scornful doubt.

What is exasperating about Asma’s piece is that he proceeds as if none of this elementary scientific method existed, or mattered. He seems to reason that, once the theoretical claims of traditional Chinese medicine are set aside, no critical assessment of the remaining claims is possible: anecdotes are all the evidence that anyone has or needs, because the choice of a treatment is always a gamble anyway. Well, of course there is an element of uncertainty in any medical treatment; in that respect, any choice of treatment is a gamble. But the fact that we don’t know exactly what is going to happen in any specific instance does not entail that we don’t know a great deal about the effectiveness of treatments. And of course it is possible that one or another Chinese treatment will eventually be found to be genuinely effective (i.e., more effective than placebo); that does not entail that we don’t already know a lot of them to be ineffective, or that we have as much reason to believe as to disbelieve the claims of effectiveness made for others of them. (See, e.g., Joe Nickell, “Traditional Chinese Medicine: Views East and West,” Skeptical Inquirer, March–April 2012.)

Pondering the “demarcation problem” is a professional specialty of philosophers. Evaluating the effectiveness of “alternative” medical treatments is not: it is a matter for medical scientists, though the results of their research can be judged and appreciated by persons without medical or other scientific training. Asma, having gotten to the end of his professional expertise by reflecting—uselessly and irrelevantly, as it emerges in the end—on the demarcation problem, proceeds as if there is simply no further basis for a critical assessment of the claims of traditional Chinese medicine. But there manifestly is: it just isn’t a matter of philosophical expertise. The specifically philosophical elements of Asma’s piece turn out in the end to be nothing but a blind for making it look as though claims of effectiveness made for traditional Chinese medicine and feng shui were beyond reach of critical examination.